Suggestions as to lines for future research : being the substance of the oration delivered at the Hunterian Society of London, February 9th, 1881 / by A.H. Smee.

  • Smee, A. Hutchison (Alfred Hutchison), 1841-1901.
Date:
1881
Catalogue details

Licence: Public Domain Mark

Credit: Suggestions as to lines for future research : being the substance of the oration delivered at the Hunterian Society of London, February 9th, 1881 / by A.H. Smee. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    determination of Wanklyn, and the oxidation method of Tidy. He should be taught to form his own judg- ment upon the value which each of these chemists attach to the presence of the various forms of organic carbon and nitrogen contained in potable waters. It would be well not to weary the student with the consideration of those branches, and the theories of organic chemistry, which are only suited to one who purposes making chemistry his profes- sion. Professor Thomas Graham has shown that gases pass through colloid septa of indiarubber in inverse ratio of the square root of their densities. Thus oxygen passed through at a greater rate than nitrogen, and carbonic acid far more rapidly than oxygen. He has also shown that both temperature and pressure within certain limits favoured the dialytic separation of the gases. The method he adopted was, to attach to the pneumatic instrument of Dr. Sprengel, small balloons or cells of indiarubber, whose action may be compared to capillary circulation of the air-cells of the lungs, and then examine the air that passed through the Indiarubber cell. It is remarkable that gutta percha, which has the same chemical formula as Indiarubber, and has been regarded by many chemists as an isomeric body, will not separate the gases. The proportion of oxygen in air dialysed by rubber appears to be 41-5 per cent., that is, the atmospheric air is deprived of one-half